Agriculture has developed the practice of injecting fertilizers and soil amendments directly into irrigation water to quickly condition soil. Gypsum is a naturally-occurring mineral which provides enhanced water penetration of certain soils. Although it has been in use for over two hundred years, it is only in the last several years that the many benefits for the use of gypsum have been touted. These benefits include:
Improves soil structure PA1 Reclaims sodic soils PA1 Prevents soil crusting and aids in seedling emergence PA1 Improves compacted soils PA1 Helps plants absorb nutrients PA1 Stops water run-off and erosion PA1 Corrects subsoil acidity as well as many others.
Until recent years, most of the gypsum used in agriculture was field spread, typically using the low-grade form found in abundance in the western United States. However, this method of application dramatically limited the benefits that gypsum provided. This is especially true in clay soils, where the gypsum would not easily penetrate when spread on the surface.
Realizing the potential that gypsum offers, different producers attempted to introduce a gypsum solution directly to irrigation water, but the low purity and coarse grind of commonly available gypsum limited the beneficial results with gypsum applied in this manner. Secondary problems, such as plugging, excessive filter backflushing, and gypsum loss, limited the success of this approach, especially in micro and drip irrigation.
The current marketers of gypsum have taken two major approaches to produce a gypsum solution which could be directly injected into irrigation water. One approach was to mine a very high grade ore of gypsum, and grind it ultra-fine, to facilitate the dissolution of this relatively insoluble mineral. The second approach, often used in tandem with the first, was to develop specialized equipment which efficiently dissolved and injected the gypsum. Both of these approaches have been effective to a degree. As a result, the amounts of gypsum sold for direct injection into irrigation water has risen.
However, the prior art has been limited by the practical applications in the field, primarily due to water quality. The prior art, a combination of the use of ultra-fine, high quality grades of gypsum with specialized solubilization equipment, in combination with pure water, leads to a gypsum delivery system that produces no clogging or plugging of the irrigation system. In reality, natural waters are often not pure. They have many impurities of many different types. Interaction of the gypsum and impurities found in naturally-occurring waters results in precipitates that cause deposits. These deposits result in plugging and loss of distribution efficiencies within the irrigation systems. As a result, the problem-free use of gypsum has been restricted to relatively pure water systems.